The gut connection to overall health, a connection Brenda and I have been exploring and educating about for many years, is growing stronger every day. Week after week, researchers around the world are linking digestive function—usually gut bacterial balance—to a range of health conditions in many different areas of the body. Particularly interesting have been the links between heart health and gut health. Brenda has blogged on a couple of these connections along the way, and many more are mentioned in our last two books, The Road to Perfect Health, and Heart of Perfect Health.
The connection between the gut microbiome and human health is currently being explored as part of the Human Microbiome Project, which I blogged about not long ago. This project has inspired a new wave of research into the effects of the gut microbiome and is delivering interesting findings. In a new study from Sweden published in the journal Nature Communications, researchers compared the gut microbiome of stroke patients to that of healthy subjects, and found some major differences.1
One interesting difference they found was that genes in bacteria required for the production of carotenoids—a group of antioxidants that includes beta carotene—were more frequently found in healthy subjects, who also had higher levels of beta carotene in the blood, when compared to stroke patients. This is interesting in light of the fact that some studies looking at the effects of beta carotene supplementation for heart health have failed to show a benefit for reduction of cardiovascular risk,2 and yet other studies have found a link between beta carotene levels in adipose tissue and cardiovascular risk.3
What all this suggests is that beta carotene is most beneficial when produced by our gut bacteria. Jens Nielsen, an author of the study, stated, “Our results indicate that long-term exposure to carotenoids, through production by the bacteria in the digestive system has important health benefits. These results should make it possible to develop new probiotics. We think that the bacterial species in the probiotics would establish themselves as a permanent culture in the gut and have a long-term effect.”
The researchers also found increases in bacteria of the genus Collinsella in stroke patients, while Roseburia and Eubacterium were increased in healthy subjects. Further, genes associated with inflammatory processes were found to be enriched in the stroke patients, while genes associated with anti-inflammatory processes were enriched in healthy subjects, “suggesting that the metagenome may contribute to the development of symptomatic atherosclerosis by acting as a regulatory of host inflammatory pathways,” stated the study. “Even though our study cannot provide evidence for direct causal effects, these findings indicate that the gut metagenome may have a role in the development of symptomatic atherosclerosis.”
This is exciting research, but more is needed to work out the details. Another author of the study, Fredrik Backhed, predicted, “By examining the patient’s bacterial microbiota, we should also be able to develop risk prognoses for cardiovascular disease. It should be possible to provide completely new disease-prevention options.”
That’s not all for the gut connection. In a study published in the journal Diabetes in 2007, it was shown that a high-fat, high-sugar diet decreases the amount of bifidobacteria in the gut and promotes intestinal uptake of bacterial cell wall antigens such as lipopolysaccharides (LPS) and peptidoglycans. These bacterial products create major upregulation (increase) of the inflammatory response in the blood, which leads to endothelial dysfunction and eventually to atheroscleroisis, or the buildup of plaque in the arteries. On the other hand, a diet that was 80–90 percent plant based (vegetables, seeds/nuts, soaked legumes, sprouted whole grains, and fruit) attracts and helps to maintain the optimum microbiome including many species of bifidobacteria and lactobacilli.
These are exciting times for the gut, indeed. To reiterate, optimal digestive function—and gut microbial balance—is the foundation upon which total body health is built.
- F.H. Karlsson, et al., “Symptomatic atherosclerosis is associated with an altered gut metagenome.” Nat Commun. 2012 Dec 4;3:1245.
- S.T. Mayne, “Beta-carotene, carotenoids, and disease prevention in humans.” FASEB J. 1996 May;10(7):690-701.
- A.F. Kardinaal, et al., “Antioxidants in adipose tissue and risk of myocardial infarction: the EURAMIC Study.” Lancet. 1993 Dec 4;342(8884):1379-84.
- P.D. Cani, et al., “Metabolic endotoxemia initiates obesity and insulin resistance.” Diabetes. 2007 Jul;56(7):1761-72.